| CPC G01C 21/005 (2013.01) | 17 Claims |
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1. A navigation apparatus configured for operation in a GPS-denied Alternative Position, Navigation, and Time (PNT) environment, the apparatus comprising:
processing circuitry; and memory, wherein the processing circuitry is configured to:
receive, from a plurality of navigation sensors, sensor measurements;
generate a plurality of navigation parameter values based on the sensor measurements, at least one of the navigation parameter values based on measurements from at least two of the plurality of navigation sensors;
provide each of the plurality of navigation parameter values to respective local Kalman filters situated in parallel to each other;
determine covariances based on first outputs from each of the Kalman filters;
determining, based on the determined covariances, a pooled covariance;
normalize, by a master filter and based on the plurality of navigation parameter values, each of the Kalman filter first outputs by the pooled covariance;
determine an output of the master filter based on the normalized first outputs and the pooled covariance;
determine at least one of the local Kalman filters is corrupted based on the output of the master filter being greater than a specified threshold value; and
in response to the determination of the corruption:
determine, based on the plurality of navigation parameter values, a distribution of degradation probability over the plurality of navigation sensors,
map, based on a Policy derived from a partially observable Markov decision process that operates based on the navigation parameter values and the covariances, the distribution of degradation probability to an action, the action indicating which of the plurality of navigation sensors is degraded, and
cause a vehicle to move based on a second plurality of navigation parameter values, the second plurality of navigation parameter values determined based on the measurement values from the plurality of navigation sensors that are not degraded and not determined based on the measurement from the plurality of navigation sensors that are degraded.
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